>> > Hello, Anyone who know what is "Illegal instruction (core dumped)" ??
>> > When I compiled and Run a fortran files in UNIX, this error comes out.
...
> More commonly an instruction was issued to the processor that
> wasn't part of the compiled code either by:
> 1) overwriting the compiled code by writing to an invalid array
>    index (although in many environments this would be trapped
>    and you would get a segmentation fault or a bus error rather
>    than surviving to issue an invalid instruction)
> 2) jumping to an unanticipated address by either
> 2a) associating a data actual argument with a procedure dummy
>     argument or
> 2b) messing up the stack (kind of requires a compiler that
>     has a callee cleans up the stack calling convention, in
>     which case invoking a procedure with the wrong number of
>     arguments or the wrong number of character arguments
>     could do the trick.)

> > Hello, Anyone who know what is "Illegal instruction (core dumped)" ??
> > When I compiled and Run a fortran files in UNIX, this error comes out.

> It's a common problem in Unix, Windows, etc., and is most often caused by
> programmer error, usually by exceeding the bounds of an array via an
> invalid access. I've cross posted to comp.lang.fortran, a more appropriate
> ng for Fortran-specific problems.

>> > Hello, Anyone who know what is "Illegal instruction (core dumped)" ??
>> > When I compiled and Run a fortran files in UNIX, this error comes out.
...
> Other causes of such a symptoms with Fortran code include;

>          a)   Calling a function or subroutine with less arguments than
>                  the actual function or subroutine accepts --- particularly
>                  if the argument in question gets modified.

>          b)   Passing an argument of wrong type, particularly a type of
>                  different physical type.  For example, passing an integer
>                  when the called subprogram expects a double precision
>                  or a string.

>>> > Hello, Anyone who know what is "Illegal instruction (core dumped)" ??
>>> > When I compiled and Run a fortran files in UNIX, this error comes out.
> ...
>> Other causes of such a symptoms with Fortran code include;

>>          a)   Calling a function or subroutine with less arguments than
>>                  the actual function or subroutine accepts --- particularly
>>                  if the argument in question gets modified.

>>          b)   Passing an argument of wrong type, particularly a type of
>>                  different physical type.  For example, passing an integer
>>                  when the called subprogram expects a double precision
>>                  or a string.
> These are for core dumps, but the OP was talking about "illegal
> instruction" in particular - SIGILL.